U.S. patent number 6,276,634 [Application Number 09/364,611] was granted by the patent office on 2001-08-21 for emergency lighting.
This patent grant is currently assigned to SAF-T-GLO Limited. Invention is credited to Peter Winstanley Bodle.
United States Patent |
6,276,634 |
Bodle |
August 21, 2001 |
Emergency lighting
Abstract
An emergency lighting system for an aircraft has
photoluminescent strips mounted on the floor rather than a string
of electrical lights. This is a better fail-safe since there is no
possibility of a failure in power supply. A channel extrusion is
secured to the floor of the aircraft and a photoluminescent strip
is held between the channel and a transparent cover member. The
photoluminescent strip has two thin layers of photoluminescent
material rather on a base layer, rather than being a calendered
product. This increases the light output.
Inventors: |
Bodle; Peter Winstanley
(Narborough, GB) |
Assignee: |
SAF-T-GLO Limited (Narborough,
GB)
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Family
ID: |
10773278 |
Appl.
No.: |
09/364,611 |
Filed: |
July 29, 1999 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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519426 |
Aug 25, 1995 |
5961072 |
Oct 5, 1999 |
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Foreign Application Priority Data
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Apr 20, 1995 [GB] |
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9508065 |
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Current U.S.
Class: |
244/118.5;
362/153; 40/570; 40/542; 362/84 |
Current CPC
Class: |
A62B
3/00 (20130101); B60Q 3/47 (20170201); B60Q
3/46 (20170201); G08B 7/066 (20130101); B64D
25/00 (20130101); B60Q 3/78 (20170201); G09F
19/22 (20130101); G09F 13/20 (20130101); B60Q
3/68 (20170201); F21S 4/22 (20160101); B64D
2011/0038 (20130101) |
Current International
Class: |
A62B
3/00 (20060101); B60Q 3/00 (20060101); B64D
25/00 (20060101); B60Q 3/02 (20060101); G09F
19/22 (20060101); G09F 13/20 (20060101); B64D
011/00 () |
Field of
Search: |
;52/174,177,33
;40/542,570 ;362/153,84 ;116/205,DIG.16 ;404/9,14,15,16
;244/118.5,118.6 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 489 561 |
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Jun 1992 |
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EP |
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964348 |
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Aug 1950 |
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FR |
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2308155 |
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Nov 1976 |
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FR |
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2224154 |
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Apr 1990 |
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GB |
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87/02813 |
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May 1987 |
|
WO |
|
93/14422 |
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Jul 1993 |
|
WO |
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94/16287 |
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Jul 1994 |
|
WO |
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94/17766 |
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Aug 1994 |
|
WO |
|
Primary Examiner: Knight; Anthony
Assistant Examiner: Chop; Andrea
Attorney, Agent or Firm: Anderson; Ronald M.
Parent Case Text
RELATED APPLICATION
This application is a continuation of a prior patent application,
U.S. Ser. No. 08/519,426, filed Aug. 25, 1995, and issued as U.S.
Pat. No. 5,961,072 on Oct. 5, 1999, the benefit of the filing date
of which is hereby claimed under 35 U.S.C. .sctn. 120.
Claims
What is claimed is:
1. An aircraft comprising:
(a) a floor along which is disposed an aisle having:
(i) a length and a width;
(ii) a first side region extending longitudinally adjacent to a
plurality of seats that are spaced apart longitudinally along said
aisle; and
(iii) a second side region spaced apart from said first side region
by substantially the width of said aisle;
(b) an exit adapted to enable passengers to leave the aircraft;
(c) a first elongate guide track mounted on said floor and
extending longitudinally along said first side region of said
aisle;
(d) a second elongate guide track mounted on said floor and
extending longitudinally along said second side region of said
aisle;
(e) each of said first and second guide tracks having a generally
flat, smooth top surface and comprising a plurality of track
sections having a length and a width, and being butted end-to-end
along the guide track;
(f) each of said plurality of track sections comprising:
(i) a photoluminescent strip extending substantially continuously
along the track section and having an upper surface and a lower
surface; and
(ii) a cover of light transmissive material extending continuously
over said photoluminescent strip to protect said upper surface;
and
(g) said photoluminescent strip being energized by an ambient light
source and operable to emit visible light for a substantial period
of time in an absence of said ambient light source and without
being energized by an electrical current, so that said first and
second guide tracks provide substantially parallel continuous
tracks of light extending longitudinally along said aisle to
identify said side regions of said aisle and to define a path along
said aisle of the aircraft in an absence of illumination from said
ambient light source, for guiding passengers along said aisle
toward the exit.
2. The aircraft of claim 1, wherein each of said plurality of track
sections further comprises a base extending along said
photoluminescent strip to support said lower surface.
3. The aircraft of claim 2, wherein said photoluminescent strip is
held substantially between opposed, generally parallel surfaces of
said cover and said base.
4. The aircraft of claim 2, wherein said cover is releasably
attached to said base.
5. The aircraft of claim 4, wherein said base and said cover have
respective co-operating interengageable formations extending
substantially continuously along each side of each track
section.
6. The aircraft of claim 5, wherein said co-operating
interengageable formations comprise downwardly projecting flanges
on said cover and upwardly projecting flanges on said base.
7. The aircraft of claim 2, wherein said cover and said base are
formed integrally.
8. The aircraft of claim 1, wherein said photoluminescent strip
includes a layer of photoluminescent material.
9. The aircraft of claim 8, wherein said photoluminescent material
emits one of a yellow and a yellow-green light.
10. The aircraft of claim 8, wherein said layer of photoluminescent
material overlies a reflective layer.
11. The aircraft of claim 1, wherein said cover has laterally
projecting side edge flanges extending longitudinally along said
track section to overlie flooring material on each side of each of
the first and the second guide tracks.
12. The aircraft of claim 11, wherein said side edge flanges are
inclined downwardly relative to said top surface of each of the
first and the second guide tracks.
13. The aircraft of claim 11, further comprising a plurality of
seats disposed adjacent to said second side region of said aisle
and spaced apart longitudinally along said aisle.
14. The aircraft of claim 1, wherein said exit is offset to one
side of said aisle from said first guide track, and wherein a pair
of exit guide tracks extend from said first guide track to said
exit to identify an exit aisle branching toward said exit.
15. The aircraft of claim 1, wherein said first and second guide
tracks include direction indicators leading to said exit.
16. The aircraft of claim 1, wherein said first and second guide
tracks are non-directional.
17. The aircraft of claim 1, wherein said photoluminescent strip
comprises a material having a photoluminescent glow property such
that from a time when said ambient light source was last incident
thereon, the photoluminescent strip has a light output of at least
445 mcd/m.sup.2 after one minute, at least 30 mcd/m.sup.2 after ten
minutes, at least 8 mcd/m.sup.2 after thirty minutes, and at least
3.8 mcd/m.sup.2 after sixty minutes.
18. The aircraft according to claim 1, further comprising a pair of
spaced-apart, parallel exit guide strips extending from one side
region of said aisle to the exit, said exit being disposed adjacent
to and offset from said aisle, each of said exit guide strips
comprising at least one track section and having:
(a) a generally flat smooth top surface;
(b) a photoluminescent strip extending substantially continuously
along said track section of the exit guide strip and having an
upper surface and a lower surface; and
(c) a cover of light transmissive material extending continuously
over said photoluminescent strip of the track section of the exit
guide strip to protect said upper surface, said photoluminescent
strip being energized by the ambient light source and being
operable to emit visible light for a substantial period of time in
the absence of illumination from said ambient light source and
without being energized by an electrical current, so that said pair
of exit guide strips provide substantially parallel continuous
tracks of light extending from said aisle to said exit in the
absence of the illumination from said ambient light source, for
guiding passenger from said aisle towards said exit.
19. The aircraft according to claim 18, further comprising
photoluminescent areas marking the exit and operable to emit light
photoluminescently in the absence of the illumination from the
ambient light source.
20. An aircraft emergency exit guide track adapted to illuminate an
escape route along an aisle extending longitudinally along a floor
of the aircraft between rows of seats, said guide track having a
substantial elongate length, a substantial width transverse to said
elongate length, and a plan area, said aircraft emergency exit
guide track comprising:
(a) a plurality of track sections butted end-to-end to form a
continuous light path, each track section comprising:
(i) an elongate base strip adapted to be secured to the floor of
the aircraft;
(ii) an elongate cover that is one of transparent and translucent
and extends over said base strip, said elongate cover having a
substantially planar, smooth top surface;
(iii) an elongate photolumninescent strip disposed between said
base strip and said elongate cover and occupying substantially all
of said plan area;
(b) said elongate cover overlying and protecting said
photoluminescent strip and said base strip supporting said
photoluminescent strip and enabling said track section to be
trodden upon without damaging said photoluminescent strip;
(c) said cover being releasably attached to the track section along
each side of said track section, enabling the cover to be readily
removable therefrom and replaceable; and
(d) said photoluminescent strip being activated by exposure to an
ambient light source and being operable to automatically emit light
photoluminescently for a substantial period of time in an absence
of illumination from the ambient light source, without further
activation.
21. A method for defining an escape path between rows of seats
arranged on each side of an aisle extending longitudinally of an
aircraft cabin, comprising the steps of:
(a) providing a plurality of elongate track sections that are
operable when activated by an ambient light source, to emit visible
light photoluminescently for a substantial period of time in an
absence of illumination from the ambient light source; and
(b) securing said track sections end-to-end to a floor of the
aircraft cabin to provide an elongate guide track extending
longitudinally along each side of said aisle adjacent to said rows
of seats so that light emitted by the elongate track sections
defines a substantially continuous path of light along said aisle.
Description
FIELD OF THE INVENTION
This invention relates to emergency lighting, typically for the
interior of vehicles, and especially, but not exclusively, to
emergency exit floor path lighting for aircraft.
BACKGROUND OF THE INVENTION
It is well known in aircraft to have strips of electrical lights
mounted at floor level to guide passengers to the emergency exit
doors of the aircraft. The strips of electric lights are powered by
an emergency battery. Such systems work well, but they have some
problems.
One problem is that they need regular servicing. The electrics
needs checking periodically and bulbs need replacing. Maintenance
of the floor-level emergency exit lights adds significantly to the
cost of maintaining an aircraft. Also the power drain caused by
running the lights adds to fuel costs.
A further problem is that if the emergency battery fails there is
no guide lighting for the passengers leading them to the exits.
Another problem is that in the event of a crash the electrical
wires connecting some or all of the floor level emergency lights
can be broken, again meaning that some or all of the floor-level
emergency lights are inoperative at just the time that they are
most needed.
It is an aim of one embodiment of the present invention to
alleviate at least some of these problems.
SUMMARY OF THE INVENTION
According to a first aspect of the invention we provide an
emergency exit path lighting system comprising photoluminescent
guide means adapted to indicate to a user a path for movement by
emitting light photoluminescently.
Thus there is no external power supply to fail and thus the system
may be fail safe. The system requires little or no special
maintenance, and may simply require wiping or other similar
cleaning. The system may be significantly lighter, cheaper and
simpler to install than previous systems.
Preferably the guide means is on the floor, but may be elsewhere
(e.g., on the side of seats).
Preferably the guide means is an elongate member.
Preferably the guide means comprises at least one, and preferably
two elongate photoluminescent tracks mounted on or near the floor.
The two photoluminescent tracks are preferably spaced apart so as
to define a path within which the user should move. Each track
preferably comprises a substantially continuous, or effectively
continuous, strip of photoluminescent material. Alternatively a
guide track may have photoluminescent regions, and
non-photoluminescent regions which alternate. In a further
alternative the photoluminescent track may comprise a row of
photoluminescent dots, circles or the like.
Preferably the substantially continuous track provides a
substantially continuous path of light from any point to an
emergency exit. An advantage of this is that a person will never be
lost as they will always have a path, to an exit, to follow. This
"continuous cueing" concept is applicable to other situations.
Alternatively the substantially continuous track may provide a
substantially continuous path of light from any point to the region
of the emergency exit and electrical lighting means may provide
lighting in the region of the emergency exit.
Preferably the system has a track which has a transparent or
translucent cover which overlays a photoluminescent guide member.
The photoluminescent guide member is preferably a relatively thin
strip of material that is supported on a support member. The track
may comprise a base member adapted to be secured to the floor, a
cover member adapted to be releasably secured to the base member,
and a photoluminescent member adapted to be sandwiched between the
base member and the cover member. Preferably the photoluminescent
member is a flexible strip. In one embodiment the support member
supports the photoluminescent strip so that it can withstand being
trodden upon. The support member preferably extends across
substantially the full width of the photoluminescent strip. The
photoluminescent member is preferably removable from the track and
is replaceable. A track may be made of adjacent discrete lengths of
profiled extrusion. The photoluminescent strip may also be provided
in discrete lengths.
Alternatively, the photoluminescent strip may be permanently
secured, for example with glue to either, the cover or the support
member. In a further embodiment the photoluminescent strip may be
co-extruded with either, or both, the cover, or the support
member.
The cover member may have a ramped, or sloping, upper surface to
facilitate the passage of wheeled vehicles such as trolleys.
Alternatively the cover member may have a low profile so that it
provides only a minimal obstruction for wheeled vehicles, such as
trolleys.
Preferably the track is laid in short sections. This has several
advantages over using a continuous run of track. One advantage is
that short runs are not as awkward to handle, another is that they
are more resilient in the event of a crash of the vehicle in which
the tracks are mounted. A continuous run may tend to be dragged
away from the body of the vehicle in such a crash.
Alternatively the track may be laid in a continuous section.
Preferably the cover member of one section may overlap the base
member of a neighboring section. An advantage of this is that
neighboring sections are loosely coupled. A clip may be provided
over the joints between the sections of the covering members.
Alternatively the sections of the covering members may have no clip
and simply butt against a neighboring section.
Preferably at each end of the track run there are provided end
caps. The end caps may be used between the short sections of
track.
Preferably to form angled joints the tracks are laid against each
other. The sections may be mitered to form an angled joint.
Preferably a layer which is impervious to UV light is used to
protect the photolurninescent layer. The UV protecting layer may be
a strip mounted on top of the photoluminescent strip or may be a
coating on the photoluminescent strip. An advantage of this is that
UV light is prevented from reaching the photolurninescent strip,
and thus the photoluminescent strip is not degraded by UV light.
Also such a layer might additionally, or alternatively, prevent UV
light from being emitted from the photoluminescent layer.
Preferably the layer impervious to UV light is made from a PVC
based material or resin, but may be from any other suitable
material. Preferably the layer impervious to UV light is
translucent to light, or other electromagnetic radiation, other
than UV light.
The transparent or translucent cover may have portions which are
stained, painted, dyed or otherwise modified to change the light
transmission properties of the cover. Preferably these portions are
opaque. An advantage of such opaque portions is that they can be
used to cover or mask poor cutting of the carpet. Alternatively the
portions may not be opaque and may used to change the color of the
light emitted from the photoluminescent strip. The method of
modifying the light transmission properties may include inserting a
colored filter underneath the cover or may include using a UV
protective layer which modifies the color of the light passing
through it.
According to a second aspect of the invention we provide a
photoluminescent member comprising a base and a layer of
photoluminescent material.
The layer may be cast onto the base. Alternatively, we may calender
a thin layer, and apply that to the base.
Previously photoluminescent members have been made by mixing
photoluminescent material with structural material and producing a
calendered product. This has the photoluminescent material spread
out throughout the depth of the member, when it is only needed at
the surface. We have appreciated that by casting a photoluminescent
layer on top of a base (or by having a thin calendered layer on top
of a base) we can achieve better results.
Furthermore, we preferably provide (e.g. cast) two layers, or more,
of photoluminescent material onto a base. This has been found to
increase the light emitted, and is easier and cheaper than casting
one thick layer. We can control the application of a thin layer
better than the application of a thick layer, and so would prefer
to provide (e.g. cast) a plurality of thin layers until we have the
thickness (or light-emitting properties) we want.
The photoluminescent layer, or layers, is preferably a vinyl layer.
The base preferably contains titanium dioxide but may contain other
whitening agents. This is believed to capture light to energize the
photoluminescent material.
The layers may be co-extruded instead of being cast together. We
may co-extrude a base and a photolumninescent layer.
According to a third aspect of the invention we provide a method of
manufacturing a photoluminescent article comprising applying (e.g.
casting) a photoluminescent layer onto a base.
According to a fourth aspect of the invention we provide an
aircraft having an emergency exit floor path lighting system in
accordance with the first aspect of the invention.
Preferably the aircraft has a substantially continuous track
mounted on or at the floor, the track comprising the
photoluminescent guide means. Alternatively the photoluminescent
guide means may be provided on the seats of the aircraft.
Preferably there is one track to one side of an aisle, for example
an aisle between seats, and another track to the other side of the
aisle. This doubles the light output in a very simple manner and
defines a path in which the user may move. Alternatively only a
single track may be provided.
Preferably there is one, or most preferably a pair, of branch
tracks leading from an aisle track to an emergency door. Most
preferably the emergency door, or the region of the doorway, is
also marked (preferably bounded) by photoluminescent areas.
Alternatively there may be no tracking in the region of the
emergency door. The guide means in the region of the emergency door
may comprise an electrical or other guide means.
The photoluminescent floor-level emergency exit lighting system may
be provided as original equipment, or it may be retrofitted to
existing aircraft.
According to a fifth aspect of the invention we provide a method of
reducing the cost of maintaining an aircraft's emergency exit floor
path lighting system comprising having a photoluminescent emergency
exit floor path lighting system instead of an electrically powered
system.
Thus the maintenance required may simply be cleaning.
According to a sixth aspect of the invention we provide a method of
reducing the cost of maintaining an aircraft's emergency exit floor
path lighting system comprising removing an existing electrically
powered floor path system and replacing it with a photoluminescent
system.
Preferably when the electrical system comprises a line of lights in
a channel track we remove the lights, introduce a support member
into the channel, and introduce a photoluminescent strip on top of
the support member. Preferably a cover is applied over the strip
and is secured to the existing channel track.
The photoluminescent strip may be attached to the carpet of the
aircraft. Preferably the photolumninescent strip is attached to the
carpet using ultrasonic welding, but may be attached using gluing
or other method.
Preferably the photoluminescent strip is covered in a protective
see-through material. Preferably the protective material is
poly-carbonate, but may be any other suitable see through material,
as appreciated by a man skilled in the art.
According to a seventh aspect of the invention we provide a method
of reducing the cost of installing, or modifying the layout of, an
aircraft's emergency exit floor path lighting system comprising
securing the aircraft's emergency floor lighting system to the
floor of the aircraft through the carpet on the floor (instead of
cutting the carpet around the lighting).
This reduces the amount of cutting of the carpet that is required
to match it to the floor path lighting system, which makes it
quicker and cheaper to install the carpet. It also means that if
the layout of the floor path lighting is changed the existing
carpet can still be retained since it does not have great big holes
in it at the old location of the lighting system.
It will be appreciated that the carpet extends under the floor path
lighting system.
Preferably a backing member (e.g., a strip or plate) is secured to
the floor of the aircraft where the lighting is to be
positioned.
Preferably the carpet is laid on top of the backing member.
Preferably locating means is provided on the backing member to
locate the lighting. The locating means may be holes or studs which
co-operate with studs or holes, respectively, on the lighting.
Such a system has an advantage that cutting of the covering carpet
is reduced, resulting in a lower wastage of the carpet, and making
it quicker to replace the carpet, and thus the cost of refitting
the aircraft is reduced.
The lighting may be provided with a means to temporarily attach it
to the floor of the aircraft. The means may comprise Velcro.TM. (or
the like) attached to the lighting strip or may comprise clamps
secured at intervals to the cabin floor through holes in the
carpet.
According to another aspect of the invention we provide a way of
reducing the cost of fitting out an aircraft with floor-mounted
emergency exit path lighting system comprising attaching the exit
path lighting above the carpet of the aircraft. This may be
achieved by studs entering through the carpet, or by Velcro.TM., or
in any other way.
The aircraft's emergency exit floor path lighting system may be of
the known electrical system or alternatively the emergency exit
floor path lighting system may be of the photoluminescent type
disclosed in this application.
In any of the inventions disclosed it will be appreciated that the
photoluminescent strips may be substantially continuous elongate
lines, or they may be interrupted. Or circles or discs of
photoluminescent material spaced at intervals may be used as an
alternative to strips of photoluminescent material.
We have also made an interesting discovery which is useful in
photoluminescent emergency exit pathways, and more widely in
photoluminescent signs or displays generally. Up until now if we
wanted to have an arrow, or the word EXIT or other words or
pictograms, in a photoluminescent sign, or in the exit path line,
we can do it by applying an opaque layer above the photoluminescent
material, masking out the emitted light. This leaves essentially
lack markings on a light-emitting background (or vice-versa--we can
blank out the background and let the markings glow in the
dark).
We have now discovered that some dyes/stains/inks can, when applied
over a photoluminescent layer, glow in the dark with a different
color to that of the photoluminescent layer. Thus the sign can have
both the background and the markings emitting light. This makes the
markings easier to see, and means that more light, overall, is
given off by the sign.
According to an eighth aspect of the invention we provide a
photoluminescent sign or display comprising a photoluminescent
layer of a first color, and markings of a second color overlying
the photoluminescent layer, the markings being made with a dye or
ink (or the like) that, in use, when overlaid, glows in the dark
with a different color from that of the photoluminescent layer.
The color that the markings emit in the dark may not be the same
color as they reflect in daylight.
The dye or ink may simply filter out some wavelengths of light
emitted by the photoluminescent layer, allowing others to pass.
Alternatively the dye or ink may be excited by the light emitted by
the underlying photoluminescent material and may emit its own light
as a response to that excitation.
The dye or ink may itself be photoluminescent with a different
color light from that of the layer beneath it.
Preferably the base photoluminescent layer is yellow more
specifically yellow/green. Preferably the pigment has a red color
but may be another color. The pigment may be a dye, such as POLYVIN
MATT FLUORESCENT RED PM 1256 which can be obtained from GIBBON inks
and coatings of 25 Deer Park Road, Wimbledon.
The pigment may have incorporated in it a compound which is
impervious to UV light. Blocking UV light may have the advantages
disclosed hereinbefore.
According to a ninth aspect of the invention we provide a
photoluminescent sign or markings having a photoluminescent layer
and a dye, or other coloring, overlaid above the photoluminescent
layer, the dye being such that photoluminescent light is
transmitted through it, but with a changed wavelength spectrum to
give a photoluminescent light of a different color to that of the
photoluminescent layer.
Instead of transmitting some wavelengths of light emitted by the
photoluminescent layer the dye could emit light of its own.
Preferably, the sign or markings has a first region in which the
photoluminescent layer is overlaid by the dye which modifies the
light emitted to produce light of a different color, and a second
region in which the photoluminescent layer is not covered by the
dye and emits light of its natural color.
There may be more than one layer of photoluminescent material
provided with the dye, or other coloring, being provided between
the different photoluminescent layers. An advantage of this is that
the intensity of the light is increased but a different color
portion is still provided.
Preferably the first or second regions define letters, or a word,
or an information--giving graphic symbol.
The dye, or other coloring, may contain mixed Xylenes,
2-Butoxyethanol and Cyolohexanone as active ingredients.
The active ingredients may be provided in the proportions Xylenes
<10%, 2-Butoxyethanol <5% and Cyolohexanone <15%.
According to a tenth aspect of the invention we provide a
photoluminescent material or member which is also reflective.
Preferably the material or member is retro reflective.
The member or material may be provided in the form of a sheet of
material.
Preferably a layer of reflective material is provided on top of a
layer of photoluminescent material. An advantage of such a
composite is that it will act as a light source and also reflect
light, making it highly visible. Such a material may have uses in
high visibility clothing, life boats, life belts, guidance out of
buildings as well as for the emergency floor lighting of vehicles.
Such items incorporating this material are explicitly disclosed and
we may seek protection for the items per se.
Preferably the layer of reflective material is transparent in
addition to being reflective. This may allow light emitted from the
photoluminescent material to pass through the reflective layer.
Preferably the layer of reflective material is made from
micro-prism reflective material.
Preferably the reflective layer is attached to the photoluminescent
layer, using high frequency welding. Preferably the layers are
welded together using a lattice work grid pattern. This pattern of
welding may prevent the egress of dirt or water into cells created
by the welding pattern. The presence of such dirt or water in the
cells may prevent the photoluminescent material from working.
BRIEF DESCRIPTION OF THE DRAWINGS FIGURES
Embodiments of the invention will now be described by way of
example only, with reference to the accompanying drawings of
which:
FIG. 1 shows a perspective view of a retro-fitted aircraft
emergency exit floor path lighting track using existing track;
FIG. 2 shows a plan view of an original equipment aircraft exit
floor path lighting track;
FIG. 3 is a cross-section of the track of FIG. 2;
FIG. 4 shows the general arrangement of an emergency exit floor
path lighting track in an aircraft;
FIG. 5 shows detail of the track arrangement near an emergency
exit;
FIG. 6 shows detail of a track near a galley;
FIG. 7 shows an impression of what an aircraft emergency exit floor
path system according to the invention will look like in use;
and
FIG. 8 is a cross section of a further embodiment of the lighting
track.
DETAILED DESCRIPTION OF THE INVENTION
A general view of a system in accordance with the invention is
given in FIG. 4. This shows an aircraft 10 having emergency exits
12a, 12b, 12c, 12d, 12e, and 12f, and a floor mounted emergency
exit pathway indicating system 14. The system 14 comprises a track
16 having a base member 18, a cover 20, and a photoluminescent
strip 22 held between the cover and the base member. FIGS. 1 to 3
show this best. FIG. 4 shows that there are two tracks 16
associated with the aisle, and with each emergency exit route: one
to either side of the floor path.
Referring to FIG. 1, this shows a molded plastics guide track 16
that has been retrofitted to an aircraft that originally had an
electric emergency floor path lighting system. The original
plastics material base section 18 is retained. In an electrical
lighting system wires and lights are retained in a channel 21, but
in the retrofitted photoluminescent system they have been removed
and the top of the channel 21 has been closed by a plastics
material support formation 23 which is releasably snap-fitted to
hook formations at the top of the side walls of the channel 21. The
photoluminescent strip 22 is a flexible strip of about a millimeter
thick. It has a vinyl base which contains titanium dioxide or other
whitening agent and has two thin-film layers of photoluminescent
material--containing vinyl cast on top of the vinyl base. The
photoluminescent material is overlaid by a UV protective top layer
(not shown). The strip 22 has the following glow properties:
Typical Glow Duration: Initial 1300 mcd/m.sup.2 1 minute 445
mcd/m.sup.2 10 min. 30 mcd/m.sup.2 30 min. 8 mcd/m.sup.2 60 min.
3.8 mcd/m.sup.2
The photoluminescent material emits a yellow light, tinged with
green.
In a different embodiment a whitening agent other than titanium
dioxide may be used.
The cover 20 is made of a transparent plastics material. The cover
20 releasably clips on to the base section via co-operating fingers
24 and 26 provided on the base section and cover respectively. The
cover has ramped, or sloping portions 28 and 30 which make it
easier to roll a trolley over the track, and reduce the chance of
someone tripping over the track.
FIGS. 2 and 3 show a track that is similar to that of FIG. 1 except
that instead of being retrofitted to an existing electrical track
it is original equipment. Instead of having a separate support
formation 21, the plastics material base section 18 of the
embodiment of FIGS. 2 and 3 has a box-section support formation 21
integrally molded with it.
In a different embodiment the track of FIGS. 2 and 3 may be
retro-fitted.
In both of the arrangements of FIG. 1 and FIGS. 2 and 3 the support
formation supports the center of the cover 20, and the strip 22, so
that they do not collapse when someone treads on them.
FIG. 5 shows detail of the tracks 16 at the region of an emergency
exit. The tracks referenced 51, 52, are the main aisle tracks
extending longitudinally of the aircraft. Branch tracks 53, 54, 55,
56, extend, in pairs, to each emergency door, referenced as 57 and
58. This gives the passengers a lead right up to the emergency
exit. It will also be noted from FIG. 4 that all of the aisles of
the aircraft are bounded by photoluminescent track 16. This means
that if a passenger follows a track 16 in any direction he will
come to an emergency exit.
We may put arrows, or other indicia, in the track to indicate the
direction to the nearest emergency exit. We may also put words in
the track, for example "Emergency Exit".
It we do put markings on the photoluminescent tracks we prefer to
make hem with the dye POLYVIN MATT FLUORESCENT RED PM 1256 or an
quivalent colorant that also glows with light of its own color in
the dark.
FIG. 6 shows another arrangement for installing a photoluminescent
strip, referenced 60, in the flooring of an aircraft. The flooring
is a non-slip lastics material flooring that has raised sections
61. These make it difficult to mount a strip to the flooring. We
remove a channel of flooring, for example by abrading, or milling,
possibly in situ in the aircraft, to produce a flat based channel
62. The strip 60 is laid in the channel and a transparent covering
63, for example an acetate strip, is glued over the
photoluminescent strip 60. The channel 62 is wider than the strip
60 to give a surface area to which the cover 63 can be glued. The
glue is also preferably transparent. In the embodiment shown in
FIG. 6 the surface of the transparent cover strip 63 that overlays
the photoluminescent strip 60 is at about the same height as the
raised sections 61.
In a different embodiment the cover 63 may be of polycarbonate.
In a further embodiment the photoluminescent strip may be precut
and vacuum sealed between two covering strips. A self adhesive may
be applied to the bottom surface of one of the covering strips so
that the complete assembly can be easily laid into a channel
corresponding to channel 62 in the flooring of the aircraft.
FIG. 7 has a right hand portion showing the interior of an aircraft
and floor-mounted photoluminescent guide tracks, with the lights of
the aircraft on, and a left-hand portion showing what a passenger
would see with the lights off. A clear path between the parallel
photoluminescent tracks of the aisle, and the emergency exit
gangways, is defined and illuminated, for the passenger to escape.
The photoluminescence of the pair of tracks is bright enough, at
floor level, for reading.
FIG. 8 shows a further embodiment for mounting the photoluminescent
strip 80. The housing 82 is low profile, presenting a minimum
obstruction for trolleys and the like. The housing 82 has the
dimensions: height 3.0 mm, and width 43 mm.
The strip 80 is removable from the housing 82. The gap 84 in the
lower portion of the housing 82 facilitating the removal of the
strip 80.
Some detailed features of possible alternative systems which are
not shown in the drawings and/or described in detail above are:
A method of joining tracking together is preferred not to be,
continuous runs of strip. This is preferably not used because a) it
is unwieldy, and b) on impact it may drag away from the
fuselage.
Instead we prefer to use short runs. We use 2 m lengths placed butt
to butt, with the top cover of one slightly overlapping the base
section of the next. We could seal using a small strip clip over
the joint of the adjacent butting sections, but at present we do
not find it necessary.
We have developed and do intend to use end-caps. These are placed
at the beginning and end of track runs. We could use the end caps
between the 2 meter runs, but this would break the concept of
continuous cueing. This may be acceptable.
For right-angle joins as in cross-aisle, we just put the track
against each other. Proper mitering of the joint into right angles
or T-junctions could be performed if appropriate.
One way of attaching the lighting strips to the aircraft floor is
to ultrasonically weld the PLM tracking into carpeting. The results
of our secret tests so far have been successful. This invention
would include welding in the strips as they are shown in the
drawings, and alternatively welding strips covered or sealed in
polycarbonate or other protective see-through material. Instead of
welding we may prefer to glue or otherwise inserting or attaching
photoluminescent material to the floor covering.
Another variation of this theme is that we may "black" (make
opaque) the flange or edge performs of the otherwise transparent
top cover to cover up poor cutting of the carpet/floor covering.
Furthermore changing the color of the light given off by either
coloring the top cover by inserting pigment into the plastic mix or
by inserting a colored filter member between the PLM and the top
cover or by putting the pigment or filter in the UV protective
layer or below the UV protective layer of the PLM is possible.
As discussed in the introduction, we have developed yet another
concept for the utilization of the floor mounted emergency exit
path strips. A major cost in putting in lighting strips is the cost
and wastage associated with cutting up the aircraft carpet/floor
covering. This means that the carpet is thrown away each time there
is a change of layout. Consequently we have invented the idea of a
system which does not require the carpet to be cut. A backing plate
is secured to the floor of the cabin where the tracking is required
to run. This plate either has locator holes or studs, it can work
either way, along its length. The carpet is laid on top of it -and
the photoluminescent tracking (it will have to be a lower profile
than the present one) is married up and pressed home attaching to
the backing plate. Although the attachment could work male to
female, or female to male, we feel that the studs should be on the
back plate as it would be far easier to locate.
This concept of a backing member beneath the carpet to which floor
path lighting is secured, through the carpet that is between them,
also applies to standard electrical floor lighting.
In addition we feel that as an alternative we may provide a quick
release/no damage to the carpet system. This might include some
sort of Velcro concept for surface mount, or additionally or
alternatively clamps for the lighting system secured at regular
intervals on the cabin floor. The clamps might be cut into the
carpet, and when PLM is used would secure the PLM strip.
We have also invented a method of combining reflective material
with PLM vinyl such that the PLM beneath absorbs light through the
surface mounted reflective material whilst shining through the
reflective material to give off light. This combination is a great
break through as it is unique to be both reflective as well as PLM
charged. Its uses will be for high visibility clothing, lifeboats,
lift belts, and for signs in general. It will also be useful on way
guidance in buildings as well as vehicles such as cars and
lorries.
It will be appreciated that we could mount the photoluminescent
safety strips on the seats (e.g. the sides of the seats, with or
without breaks in the PL material). We could mount the strips on
the legs of the seats. Seat side mounting has the advantage that we
do not have to cut the carpet to install the system, or to
recognize the layout of the P1 safety strips within the
aircraft.
We could clip the strips to the seat/or carpet, use studs (or
releasable mechanical fasteners) use hook and fiber fasteners
(Velcro.TM.). We could weld the strips to the carpet and/or seat
sides. We could glue the strips down.
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